1. Field of the Invention
The present invention relates to agricultural harvesters, and, more particularly, to header assemblies for agricultural harvesters.
2. Description of the Related Art
Combines are used to harvest agricultural crops such as corn, soybeans, wheat and other grain crops. As the combine is driven through crop fields, the combine cuts the crop, separates the desired crop from the undesired waste, stores the crop, and discards the waste.
In a typical combine, a header is mounted to the front of the combine to gather the crop and feed the crop into the combine for processing. As the combine is driven through the field, the crop material is collected by the header and deposited into a feeder housing. The crop material is then transported upwardly and into the combine by a feed elevator located within the feeder housing. The crop material then passes through a threshing and separating mechanism. In a rotary combine, the threshing and separating mechanism includes a rotor, a threshing concave, a rotor cage, and a separating grate. As crop material passes between the rotor, the threshing concave and the separating grate, the crop material is impacted and/or rubbed, thereby causing the grain to separate from the stalk material. The stalk material that is separated from the grain is commonly referred to as material other than grain (MOG). Other types of combines are also known that perform similar functions using different mechanisms.
After passing through the threshing and separating assembly, the grain and MOG are deposited onto a grain cleaning system. The grain cleaning system of a typical combine includes a plurality of adjustable cleaning sieves, often referred to as a chaffer sieve and a shoe sieve. The sieves are typically reciprocated back and forth in opposite directions along an arcuate path. This motion has the tendency to separate the grain from the MOG. To further separate the grain from the MOG, a cleaning fan or blower is positioned so as to blow air up through the cleaning sieves. This flow of air tends to blow the MOG, which is typically lighter than grain, rearwardly and out the back of the combine. Grain, which is heavier than MOG, is allowed to drop through the openings in the sieve.
The clean grain that falls through the cleaning sieves is deposited on a collection panel positioned beneath the cleaning sieves. The collection panel is angled so as to permit the grain to flow, under the influence of gravity, into an auger trough positioned along the lowermost edge of the collection panel. The auger trough is typically positioned near the forward end of the cleaning sieves and extends along the width of the sieves. The grain collected in the auger trough is then moved by an auger towards the side of the combine where it is raised by a grain elevator and deposited into a storage tank or grain tank. Other systems also exist that can utilize, for example, a loop conveyor system which eliminates the need for a conventional cross auger.
To convey cut crop material into the feeder housing from the header, an infeed assembly can be included in the header that directs the cut crop into a middle of the header and then utilizes rotating fingers to push the cut crop material toward the feeder housing. To increase the conveyance rate of cut crop material into the feeder housing, multiple fingers can be included in the infeed assembly.
One possible infeed assembly that can be used is described in U.S. Pat. No. 4,217,672 to Olivari. The infeed assembly taught by Olivari includes rake-like members, which can be fingers, on a revolving shaft that sweep and pick up leaves and other debris from a lawn and move them upwards within the housing of the device. The fingers extend outwardly from the shaft and the ends pass through apertures formed in a drum. The drum is off-center in relation to the shaft of the fingers so that in the revolving of the mechanism the ends of the fingers move back and forth through the apertures in the drum. The fingers taught by Olivari are made of a flexible material so that they can bend during operation as the relative position of the shaft to which they are attached changes in relation to the apertures in the drum. This flexibility allows the fingers to operate in the configuration taught by Olivari to push leaves and other light, flimsy materials, but makes them unsuitable for pushing heavier materials that would cause the fingers to bend during contact rather than the material being pushed by the fingers.
Another assembly that includes multiple fingers is a parts separator described by U.S. Pat. No. 4,484,684 to Tetreault. The separator taught by Tetreault includes a drum mounted for rotation about a first horizontal axis that constitutes an outer separator element, and an inner separator element mounted within the drum for rotation about a second horizontal axis which is spaced from and parallel with the first axis. The drum has apertures in its outer surface and the inner separator element includes pins which extend through the apertures, so that rotation of the inner and outer separator elements about their respective axes causes the outer end of each pin to reciprocate within the aperture between an inner position where the end of the pin is flush with the outer surface of the drum to an outer position where the end of the pin extends beyond the outer surface of the drum. The pins are attached to spindles, with most of the spindles being free to pivot and one of the spindles being fixed against pivoting. The spindles are driven by a shaft, with the fixed spindle's pins driving the drum. One problem with this arrangement is that the arrangement of the spindles is complicated and each spindle must extend the length of the inner separator element. Further, to keep one of the spindles fixed, bushings are placed in apertures of the drum to hold the fixed spindle's pins in place, which can wear away and allow the previously fixed spindle to pivot.
What is needed in the art is an infeed assembly that can overcome some of the previously described disadvantages of the prior art.